Acute bronchitis is the deep, wet, or dry cough that comes on and lingers after an infection, such as a cold, sinusitis, or the flu. The cough, which may start out dry and then turn productive, is the body's way of expelling infected mucus from the lungs. An episode of bronchitis may last for one to two weeks, and because a virus usually causes it, antibiotics may not be helpful.
Chronic bronchitis develops in the continual presence of irritants such as environmental allergies and damp weather; it sometimes results from food allergies. It often begins as acute bronchitis that returns every few months and, if the irritants are not removed, will develop into a constant cough, often accompanied by breathlessness and sometimes wheezing. The weakened condition of the lungs leaves the body vulnerable to infections like acute bronchitis, pneumonia, and emphysema. The best treatment is to eliminate the irritants that caused the condition. This is accomplished by identifying the offending allergens and removing them or reducing your body's sensitivity to them.